Disk feeder having material scraper and material agitators



Jan. Z7, 19. E. HARPER 2,435,039

DISK FEEDER HAVING MATERIAL SCRAPER AND MATERIAL AGITATOR Filed Jan. 12,1944 s Sheets-sheaf. 1

%jfl. 1. INVENTOR v LYNDUS a. mmmsn BYEuA w 27, 1948. HARPER 2,435,039

DISK FEEDER HAVING MATERIAL SCRAPER AND MATERIAL AGITATOR I Filed Jan.12 1944 3 Sheets-Sheet 2 2s 7 so ENVENTOR LVNDl/fi E. HARPER Jan. 27,194-8. L. E. HARPER msx FEEDER HAVING MATERIAL scEEP E AND MATERIALmmmoa Filed Jan. 12, 1944 3- Sheets-Sheet s HNVENTOR LYNDUS 5. HARPERATTORNEY Patented Jan. 27,1948

DISK HAVING MATERIAL SOBAPER AND MATERIAL AGITATORS Lyndus E. Harper,Kansas City, M0,, assignor to Omega Machine Com corporation of Missouripany, Kansas City, Mo., a

Application January 12, 1944, Serial a... 518,019 Claims. (01. 222-210)1 A My invention relates to feeding devices, and more particularly to agrooved disk feeder.

It is a purpose of my invention to provide a feedin device that isadaptedto accurately feed very small quantities of finely dividedmaterial at a controlled rate, comprising a hopper that has a bottomthat is rotatable, and which bottom is provided with an annular groovetherein that is of uniform cross section, said bottom member and thebottom portion of said hopper being so related to each other that aportion of the bottom member having the groove therein is within thehopper and a portion thereof is outside the hopper, and to provide meansengaging the bottom member of the hopper for removing the material fromthe groove therein to discharge the same onto or into a. device to whichthe finely divided material is to be fed.

It is a particular purpose of my invention to provide means forcontrolling the feed of said material, comprising means for rotating thebottom member at a controlled rate, which means is adjustable and which,preferably, comprises a variable speed transmission means and means foradjusting the same to obtain the desired rate of feed of said device.

It is a particular purpose of my invention to provide in a device of theabovementioned character a hopper that has a vertical wall portion, orsubstantially vertical wall portion at the bottom thereof, the bottomedge of which is held in firm contact with the substantially plane topface of the bottom wall member of the hopper so as to provide a tightjoint preventing escape of the finely divided material between saidplane top face of said bottom wall member and the bottom edge portion ofthe substantially vertical wall of said hopper, said means, preferably,comprising means for exerting a pressure between said bottom andvertical wall portions, which means, preferably, comprises resilientmeans for yieldingly holding said hopper in engagement with the bottomwall member and exerting sumcient pressure thereon to provide a tightjoint between the body portion of the hopper and said bottom wall. Saidbottom edge of said substantially vertical wall portion also serves asmeans for leveling off the material that will accumulate in the annulargroove in said bottom member as the same leaves the hopper during therotation of said bottom member relative to the body portion of thehopper, so that the same quantity of material is discharged from thehopper per unit of length'through the groove dueto rotation of saidbottom wallmemher at all times, the groove being, of course, of uniformcross section throughout.

The relationship of the body portion of the hopper and the bottom wallmember and the resilient means is such that the yielding or resilientmeans will compensate for any wear of the parts that might otherwiseprevent a tight Joint between the bottom wall and the remainder of thehopper that might cause leakage of the finely divided material betweenthe top substantially fiat or plane face of the bottom wall and thebottom edge of the substantially vertical wall of the hopp r contiguousto said bottom wall.

It is another purpose of my invention to provide means for removing thematerial from the groove at a predetermined station or location, so thatas the groove passes this. station or location all of the material willbe removed from said groove and discharged from the bottom wall over theedge thereof to pass by gravity toward the device or apparatus into oronto which the finely divided material is to be fed, said meanscomprising a scraper member that has a portion that engages the top faceof said bottom wall and which has a downwardly projecting portion of thesame cross sectional shape as the cross sec tional shape of the grooveengaging in said groove, so as to remove all of the material therefromas the same contacts said scraper member, so as to cause said materialto travel over the top face of said bottom wall, as said bottom wallrotates, and outwardly toward the peripheral edge'or rim thereof to dropoil said rim or edge by gravity.

It is another important p rpose of my invention to provide means forobtaining a substantially even distribution of the material dischargedby the above referred to scraping means from the rotatable bottom wallmember, onto or into a member to which the material-is fed, comprising asifter or screen that is shaken constantly to spread or evenlydistribute the material that is being discharged from the edge of thedisk onto or into a member located below said sifter or shaking screenmember.

It is still a further purpose of my invention to provide a device of thabove mentioned character, in which the rate of rotation of therotatable bottom 'wall member can be varied to any extent desired toobtain the desired rate of feed of the material from the rotatablebottom wall member between a quantity approaching zero and apredetermined maximum rate of feed for the feeder, comprising variablespeed transmission means, the output shift of which drives saidrotatable feeding member, said driving means comprising a shaft that isdriven at substantially a constant rate of speed, which rotates therotatable feeding member through said variable speed transmission, andwhich is provided with means rotating therewith that operates the sifteror shaking device at substantially a uniform rate of oscillation orshaking, no matter what the rate of rotation of the rotatable feedingmember may be.

It is another important purpose of my invention to provide means forremoving the finely divided material from the rotatable feeding member,to dmcharge the same therefrom, comprising a scraper member, and meansfor holding the scrap- 1 er member in contact with the surface of therotatable feeding member and in position in en.- gagement with the wallsof said groove, which is wear compensating so that said scraper will bein constant engagement with the walls of the groove and the top face ofthe rotatable feeding member, said means comprising a member that exertspressure on said scraper member, which, preferably, is resilient meansexerting a downward pressure on said scraper member, so that the bottomedge thereof will be held under a predetermined pressure in contact withthe surfaces from which the material is to be scraped, and to provideadjusting means for said resilient means.

It is another purpose of my invention to provide means within the hopperengaging the top surface of said bottom wall member in such a manner asto completely fill the groove in said bottom wall member before saidgroove leaves the confines of said hopper, so as to assure a uniformquantity of material is leaving said hopper per unit of length of saidgroove as said groove passes out of the hopper during rotation of saidrotatable member.

Said hopper is further, preferably, provided with means for agitatingthe contents thereof so as to provide a uniform feed by gravity of thefinely divided material onto said rotatable bottom member, comprising aplurality of agitator members rotating with said rotatable bottom memberand a fixed agitator member on said hopper, said rotatable agitatormembers comprising a member directed away from said rotatable bottomwall member into the upper portion of said hopper, and a member directedtoward said bottom wall member, but spaced therefrom It is a specificpurpose of my invention to provide a device of the above mentionedcharacter, in which the rotatable bottom member is made in the form of adisk having an annular groove therein concentric with the center thereofclosely adjacent the periphery of said disk, said hopper having a wallportion at the bottom end thereof that has a substantially verticallyextending portion that is substantially annular in character, the axisof rotation of said disk-like member being eccentric to the center ofsaid annular wall portion of said hopper, so that a portion of said diskhaving the groove therein lies within the hopper and a portion thereoflies externally of said hopper.

My invention is adapted for feeding finely divided material to otherfinely, divided or similar material that is in a dry state, by feedingthe same onto moving means carrying said material to also adapted forfeeding finely divided material of a soluble character into a liquid,comprising means for agitating the liquid after the finely dividedmaterial passes into the same so as to prowhich the finely dividedmaterial is fed, and is vide a uniform mixture of said soluble finelydivided material and said liquid, and so constructed and arranged as tofeed said soluble finely divided material into the main stream of saidliquid at a substantially. uniform rate.

Other objects and advantages of my invention will appear as thedescription of the drawings proceeds. I desire to have it understood,however, that I do not intend to limit myself to the particular detailsshown or described, except as defined in the claims.

In the drawings:

Fig. 1 is a view partly in elevation and partly in section, partlybroken away, of my improved feeding device.

Fig. 2 is a view partly in horizontal section, taken substantially onthe line 2-2 of Fig. 4, and partly in elevation, of the feeding deviceshown in Fig. i, partly broken away, the cover plate of the feeder beingomitted.

Fig. 3 is a view partly in vertical section and partly in elevation,taken substantially on the line 3--3 of Fig. 1, the-hopper being omittedand the upper part of the feeding device being broken away.

Fig. 4 is a fragmentary vertical sectional view on an enlarged scalethrough the feeding device and a portion of the variable speedtransmission means for driving the same.

Fig. 5 is a fragmentary view partly in section, taken substantially onthe line 5-5 of Fig. 2.

Fig. 6 is a fragmentary sectional view through the variable speedtransmission driving means, taken substantially on the line 6-8 of Fig.4.

Fig. 7 is a fragmentary elevational view of a modified form of feedingdevice, and

Fig. 8 is a section taken substantially on the line 8-8 of Fig. 7.

Referring in detail to the drawings, my improved feeding devicecomprises a frame ll, which has a motor ll mounted thereon, said motorbeing mounted on a bracket 12 on said framework. The motor drives ashaft 13 through the pulleys l4 and I5, over which the belt ll operates.Said shaft li is the drive shaft of a variable speed transmission devicemounted in a housing H on the frame ii. Said variable speed transmissionis constructed in a manner similar to that shown in my applicationSerial No. 500,- 032, filed August 26, 1943. The, input shaft isoperated by drive shaft 3 at a uniform speed and is indicated by thenumeral 18 in Fig. 6 and has mounted thereon a plurality of cams, suchas the cam It, with which followers 20, such as disclosed in my abovereferred to copending. application, cooperate to drive the output shaft2|, which is provided with a worm 22 meshing with the worm wheel 23 onthe shaft 24. The position of the followers relative to the cams isadjustable in a manner described in said co-pending application by meansof a lever 25 provided in acouvenient location, preferably, on the topof the housing II, a suitable scale or dial 26 being provided, withwhich a pointer 21 on the lever 25 cooperates to indicate the setting ofthe variable speed transmission device to obtain the desired rate offeed of the apparatus, as will be explained below. The rate of feed ofthe apparatus is dependent upon the rate of rotation of the shaft 24 andthe rate of rotation of the shaft 24 is dependent upon the adjustment ofthe followers relative to the cams, and accordingly the scale or dial 26can be calibrated to indicate rate of feed in any suitable unitsdirectly, if this is desirable.

Mounted upon the housing ii is a housing 2|,

will be obvious from Fig. 2. Said housing has a transverse wall 23provided with a bearing 33 for the shaft 24, said bearing, preferably,comprising a boss 3| extending upwardly from the transverse wall 23 andserving as a spacing member within which is mounted a bearing member 32of anti-friction metal. the details of construction of the bearing beingshown in Fig. 4. Rotatably mounted on the boss 3! is a disk-like member33, said disk-like member being provided with a depending annularreenforclng rib 34 and an annular groove 33 opposite said reenforcingrib in the top face thereof. The top face of said disk-like member isfaced 03 so as to be substantially plane or flat, except for the annulargroove 35, which is machined so as to be of uniform cross sectionthroughout its entire length.

engaging the tapering wall 4! of the hopper, and a downwardly andoutwardly curved flexible agitating member II, also made of suchmaterial as spring wire, which extends downwardly toward the top surfaceof the disk-like member 33,

. but is spaced therefrom. A plurality of agitator Extending upwardly atthe axial center of the disk-like member 33 is a tubular sleeve-likeextension 36. The shaft 24 extends into this tubular member 33 and has atransversely extending rib ortion 31 thereon that is seated in atransversely extending groove in the lower end of the stub shaft 38,which is fixed to the sleeve-like member 38 so as to rotate therewith,thus providing a detachable connection between the disklike member 33and the shaft 24, permitting said disk-like member to be readily placedin position on the upper end of the shaft 24 projecting above the top ofthe transverse wall 23, said disk-like member 33 thus being driven bysaid shaft 24 at the rate of rotation thereof.

Said feeding device is provided with a hopper having an uppersubstantially cylindrical body portion 39 provided with a removablecover member 40 and a lower tapering body portion 4i termlnating in anannular substantially vertical wall portion 32, which is, preferably,circular. but of considerably smaller radius of curvature than thedisk-like member 33. The bottom edge of the vertical wall portion 42 isfinished off to lie in a plane so that the same will have closed contactwith the top face of the disk-like member 33, which comprises the bottommember of the hopper. Said lower body portion 4| is provided with alaterally extending flange 43, which is provided with a depending lip 44overlapping the vertical housing 23, said flange 43 thus providing acover member for said housing overlying the disk 33, but not extendingover the entire housing so that the operation of the apparatus can beobserved through the opening thus provided. A plurality ofscrew-threaded headed members 43 are provided mounted in the verticalwall portion of the housing 23, coil springs 41 being provided betweenthe heads on the members 43 and the flange 43 to thus hold the bottomedge of the annular wall 42 in such tight engagement with the plane topsurface of the disk, that the finely divided material in the hopper willnot escape between the bottom edge of the vertical wall ortion 42 andthe flat or plane top surface ofsaid disk-like member 33. The proportionof the parts is such that when the wall portion 42 is in engagement withthe top of the disk the wall portion 43 will not be in engagement withthe top edge of the vertical wall 23 of the housing.

The shaft portion 33 has a collar 43 fixed thereto-at its upper end.Agitator members are provided in the hopper and these are secured to thecollar 43 and, preferably, comprise an upwardly and outwardly curvedagitator member 53. which is made of flexible material, such as springwire,

members is also provided sweeping the top surface of the disk-likemember 33 to assure fillin! of the groove 33, said agitator members 32being also made of spring wire and being curved as shown in Fig. 2, thenormal curvature of said members being substantially that shown for thetwo agitator members 32 on the left side of the shaft 33. Each of saidagitator members 52 comprises a portion 33, which extends parallel tothe top face of the disk 33, 9, depending end portion 54 mounted in anopening in the disk 33 adjacent the tubular member 33, and anhpstandingend portion 53, which is in engagement with the wall 42. A collar 53 isalso, preferably. provided on the'member 33, which has slots in itsbottom face accommodating the wire agitator members 32. Cooperating withthe agitator members Ii and 32 is a fixed agitating member 31, which issecured to the hopper wall 4! and has a portion 53 that extendssubstantially parallel to the top face of the disk-like member 33 and aslightly upturned end portion 33 at the end thereof nearest thesleeve-like member 33. The rotatable members BI and 52 in cooperationwith the stationary member 33 thoroughly agitate the material near thebottom of the hopper and cause the groove 35 to be completely filled. Itwill be noted that as the upturned portions 55 of the agitator members32 slide along the wall 42 (see Fig. 2), due to the fact that theparallel wall portion 42 is eccentric to the axis of rotation of saidmembers, these will be flexed so as to be bent considerably out of theirnormal shape on the righthand side of the hopper, as viewed in Fig. 2,which causes a sliding movement of the members 32 relative to the topface of the disk-like member 33 and thereby causes said members 32 tocross the annular groove 35 twice during each rotation of the apparatuscomprising the disk-like member 33 and the parts rotating therewith;Thus, although the agitator members 52 rotate with the disk-like member,the same also move relative to the disk-like member to aid in fillingsaid groove 35 uniformly.

Mounted on the flange-like cover member 43 is a rod-like member 63constituting a bracket. upon which the scraper member BI is mounted.Said rod-like member has a threaded end extending through an opening inthe scraper 3i and a nut 62 is screw-threaded thereon for holding thescraper 6| from being carried along with the disk 33 in its rotationwith the shaft 24. The bracket 33 eiitends through an opening in thecover 43 and there is sufficient looseness of the parts that saidbracket 63 can go through a swinging movement permitting movement of thescraper 8| relative to the cover member 43 toward and away from thedisk-like member 33.

Said scraper has a substantially straight bottom edge 33, which engagesthe flat top face of the disk-like member 33 and a downward projection34 conforming in shape to the cross sectional contour of the groove 35.Said projection 34 and the straight edge 63 are held in firm contactwith the walls of the groove and the top face of the disk 33 adjacentsaid groove by means resiliently pressing downwardly with a springpressure on said scraper member 3|, said means, preferably, comprising arod-like member 33 of resilient, materiahwhich has an upwardly ex-.

tending end portion 88 mounted inan opening in the cover member 48 andwhich engages the top edge of the scraper member 8!, as will be obviousfrom Fig. 5, the end of said member 85 opposite the end 68 being mountedin one of the notches or recesses 8-1 of an angular bracket 88 mountedin the housing 28, preferably, being secured to the vertical wall 28thereof in fixed position. It will be obvious that the pressure exertedby the spring 65 canbe varied as desired, by adjustment of the endthereof relative to the bracket 68 byher 33 and that the dependingprojection 84 thereof will engage firmly with the walls of the roove 35to thus remove all the material from the groove and prevent any escapethereof beyond the scraper member ii as the disk 83 re. tates in aclockwise direction, as viewed in Fig. 2. It will be noted that thescraper 8! does not extend radially of the disk, but at an oblique angleto the radius so that the material .will be forced in an outwarddirection over the periphery of the disk, due to the movement of thedisk 33 relative to the scraper; The groove It will have been filledfully with the finely divided material in the hopper when the samereaches the point where said groove passes under the bottom edge of thevertical wall 42 in the lower end of the hopper. As the various portionsof the disk-like member in its rotation pass under the bottom edge ofthe wall 42, said bottom edge of said wall will remove all of thematerial from the top fiat face of the disk-like member 33-as said facepasses out of the hopper below said Well 42, except for the materialcontained in the annular groove 35, which material will be leveled offso that there will be a uniform amount of said material for each unit oflength of the groove 35 therein as it passes out of the hopper, thiscondition existing until the portion of the disk containing the materialin the groove reaches the scraper 6i, whereupon it will be removed anddischarged over the peripheral edge of the disk to drop by gravity intothe housing 28.

At the point where this gravity discharge of the finely divided materialfrom the disk takes place, the bottom wall 29 of the housing is providedwith an opening 59, said housing having a tubular housing 18 dependingtherefrom and aligning with the opening 68. Said depending housing 18 isprovided with'a pair of bearing members SH, which may be of aself-lubricating character, and in which the shaft portions or pivotmembers 12 are rotatably mounted. Said pivot members or shaft portions12 extend from a frame 13 of a sieve or sifter ll of wire, or similarforaminous material. A lever 15 is ,fixed to .one of said shaft members12 so as to move therewith. Rotatably mounted on the lower end of saidlever 15 is a, wheel or roller 18, which is, preferably,

provided with a resilient rim portion, or rubber her 88, which isprovided with a plurality of high or. raisedportions 8| thereon thatengage said roller or wheel 18 at the rim portion 'I'I thereof tooscillate said lever l5 and to thus oscillate or shake the sifter II.The cam 88 is fixed to the shaft #8 to rotate therewith, as will beobvious from Fig. 4. a

Said shaking or oscillating sieve or sifter com; prises adistributingmeans to assure even distribution of the finely divided material over anarea below said sifter or sieve. The material can be discharged into oronto any desired stationary or movable means, but if the material isbeing measured by means of the disk feeder so that a predeterminedquantity thereof is to be evenly distributed in a substantially uniformmanner through some other material, it is desirable to provide meansmoving at a uniform rate. such as the belt conveyor shown at 82, whichis shown as being supported on rollers 88 in a conventional manner, uponwhich a, substantially uniform layer of material is provided, to whichthe finely divided material fed by my improved disk feeder is supplied.-

While the form of the invention shown in Figs. 1 to 6, inclusive,discloses means for feeding the finely divided material to a dry, orsubstantially dry, material, which also is, preferably, a finely dividedmaterial, means may be provided for feeding such a finely dividedmaterial to a liquid, in which case the feeding mechanism is,preferably, the same as previously described, except that the'siftingmeans is omitted and instead a housing Hi is provided, as shown in Figs.'7 and 8, which is liquid tight, and is. provided with a bottom wall 8,with which a discharge pipe 85 is in liquid tight connection, said pipeleading to a T 88 provided with a nozzle 8.8 in a liquid line 81,through which liquid flows from left to right, as shown in Fig. 7, towhich the finely divided material is supplied. The finely dividedmaterial in such case is, preferably, soluble in the liquid, and inorder to assure a thorough mixture of the liquid and the finely dividedmaterial, which is substantially uniform. the liquid inlet conduit 88leading into the container Ill leads into the same substantiallytangentially thereof, as will be obvious from Fig. 8, said inlet conduit8| being connected with the liquid conduit 81 through the T 89 andsuitable pipe fittings, including a. valve through the feeding device,whereby the accuracy of the feed can be determined.

What'I claim is:

1.In a device for feeding finely divided material at a controlled rate,a hopper, a disk mounted for rotation about an axis passing through itscenter and forming the bottom of said hopper, said disk having a planetop face except for an annular groove of uniform cross section thereinconcentric to said axis of rotation, said hopper having a continuousimperforate cylindrical wall portion of less diameter than the annulusof said groove contiguous to said disk, said wall portion having acontinuous circular bottom edge lying aes'aoso 9" in a'plane parallel tosaid top face and adapted to engage said top face of said disk face toface, said circular edge being'eccentric to said axis so that a portionofsaid groove lies within said hopper and a portion of said groovelies-externally of said hopper,.means for pressing said bottom edge intotight engagement with said top face to prevent escape of finely dividedmaterial from said hopper except through emergence thereof in saidgroove under said bottom edge due to rotation of saiddisk, said bottomedge extending uninterruptedly across said groove to level the materialin said groove to fill it to the top face of said disk and provide auniform depthof said material in said groove as said groove emerges fromsaid hopper, means engaging said groove externally of said hopper'toremove all saidmaterial therefrom at a predetermined station duringrotation of said disk. means for rotating said.

said disk having a plane top 'face except for an annular groove ofuniform cross section therein concentric to said axis of rotation, saidhopper having a continuous imperforate cylindrical wall portion of lessdiameter than the annulus of said groove contiguous to said disk, saidwall portion having a continuous circular bottom edge lying in a planeparallel to said top face and adapted to engage said top face of saiddisk face to face, said circular edge being eccentric to said axis sothat a portion of said groove lies within said hopper and a portion ofsaid groove lies externally of said hopper, means for pressing saidbottom edge into tight engagement with said top face to prevent escapeof finely divided material from said hopper except through emergence.

thereof in said groove under said bottom edge due to rotation of saiddisk, said bottom edge extending uninterruptedly across said groove tolevel the material in said groove to fill it to the top face of saiddisk and provide a uniform depth of said material in said groove as saidgroove emerges from said hopper, means engaging said groove externallyof said hopperto remove all said material therefrom at a predeterminedsta tion during rotation of said disk, means for rotating said disk at apredetermined rate, and means for adjusting the rate of rotation of saiddisk to adjust the rate of feed of said finely di vided material,comprising a movable controlling member and means for varying said rateof rotation in direct proportion to the movement of said controllingmember. I

3. In a device for feeding finely divided material at a controlled rate,a hopper, a disk mounted for rotation about an axis passing through itscenter and forming the bottom of said hopper, said disk having a planetop face except for an annular groove of uniform cross section thereinconcentric to said axis of rota-. tion, said hopper having a continuousimperforate cylindrical wall portion of less diameter than the annulusof said groove contiguous to said disk, said wall portion having acontinuous circular bottom edge lying in a plane parallel to said topface and adapted to engage said top face of said disk face to face, saidcircular edge being eccentric to said axis so that a portion of saidgroove lies within said hopper and a porengagement with said top face toprevent escape I of finely divided material from said hopper exceptthrough emergence thereof in said. groove under said bottom edge due torotation of said disk, said bottom edge extending uninterruptedly acrosssaid groove to level the material in said groove to fill it to the topface of saiddisk and provide a uniform depth of said material in saidroove as said groove emerges from said hopper,

a scraper externally of said hopper having a projecting portion of thecross sectional shape of said groove engaging in said groove at apredetermined station and having straight edged portions on oppositesides of said projecting portion engagin the plane face of said disk onopposite sides of said groove, resilient means holding said scraper inpressure engagement with said plane face and groove, means for rotatingsaid disk at a predetermined rate, and means for adjusting the rate ofrotation of said disk to adjust the rate of feed of said finely dividedmaterial.

4. In a device for feeding finely divided material at a controlled rate,a hopper, a disk mounted for rotation about an axis passing through itscenter and forming the bottom of said hopper, said disk having a planet'op face except for an annular groove of uniform cross section thereinconcentric to said axis of rotation, said hopper having a continuousimperforate annular wall portion terminating in a continuous circularbottom edge. of less diameter than the annulus of said groove and lyingin a plane parallel to said top face and adapted to engage said top faceof said disk face to face, said circular edge being eccentric to saidaxis so that a portion of said groove lies within said hopper and aportion of said groove lies externally of said hopper, flexible membersengaging the plane face of said disk and rotatable with said disk withinsaid hopper about an axis eccentric to said annular wall portion andengaging said wall portion to move across and fill said groove with saidfinely divided material, means for pressing said bottom edge into tightengagement with said top face to prevent escape of finely dividedmaterial from said hopper except through emergence thereof in saidgroove under said bottom edge due to rotation of said disk, said bottomedge extending uninterruptedly across said groove'to level.

the material in said groove to fill it to the top face of said disk andprovide a uniform depth of said material in said groove as said grooveemerges from said hopper, means engaging said groove externally of saidhopper to remove all said material therefrom at a predetermined stationduring rotation of said disk, and means for rotating said disk at apredetermined rate.

5. In a device for feeding finely divided material at a controlled rate,.a hopper, a disk mounted for rotation about an axis passing through itscenter and forming the bottom of said hopper, said disk having a planetop face except for an annular groove of uniform cross section thereinconcentric to. said axis of rota- 'aaa aoao 11 hopper and a portion ofsaid groove lies externally of said hopp r. agitating means in saidhopper comprising means extending above the top of .said disk androtatable therewith, a flexible member secured to said means and havingan upwardly extending portion curving upwardly and outwardy therefromand engaging the hopper wall and having a downwardly extending portioncurving downwardly and outwardly therefrom. and a stationary,flexible'member projecting inwardly from the hopper wall adjacent thepath of said downwardly curved flexible member, means for pressing saidbottom edge into tight, engagement with said top face to prevent escapeofflnely divided material from said hopper except through emergencethereof in said groove under said bottom edge due to rotation of saiddisk. said bottom edge extending uninterruptedly across said groove tolevel the material in said groove to 1111 it to the top face of saiddisk and provide a uniform depth of said material in said groove as saidgroove emerges from said hopper, means engaging said groove externallyof said hopper to remove all said material therefrom at a predeterminedstation duringrotationof said disk, and means for rotating said disk ata predetermined rate.

- LYNDUB E. HARPER.

The following references are of REFERENCES CITED record in the file ofthis patent:

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